const charts = [
  'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
  'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
  '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
  '_', '-', '$', '%', '&', '@', '+', '!',
]

export const random = (length: number, chars?: string[]) => {
  const chs = chars || charts
  const res = []
  for (let i = 0; i < length; i++) {
    const x = Math.floor(Math.random() * chs.length)
    res.push(chs[x])
  }
  return res.join('')
}

export const randomNumber = (length: number) => random(length, charts.slice(52, 62))

export const randomAlphabet = (length: number) => random(length, charts.slice(0, 52))

export const randomAlphabetNumber = (length: number) => random(length, charts.slice(0, 62))
